The Aprilaire #45 Comparable Humidifier Replacement Filter (2-Pack) by Tier1 is a pad replacement to prevent mineral build-up on your current, old pad from getting into your home's air. The humidity in your home helps maintain a healthy respiratory system. This product is designed to protect your home from harmful pollutants and create a peaceful, healthy place to breathe for your whole family. The Aprilaire humidifier filter traps minerals, sediment, and microorganisms, delivering air filled with moisture and free of contaminants, creating a breathing environment that is healthier for the entire family. Order today!